02 K40, MAJOR problem...what will Kahr do?

[jocko]

oh my that lower colt commander with ther dual back strip stippling gives me a bo@ner to no end. I take it,u did the work even, wow, no double wow that is awesome.

And you don't have to be a gentleman about it. LOL, I think most will tell u that is not ol jocko..

[Tinman507]

God there are some artists on this forum.
What a completely beautiful firearm.

[jg rider]

oh my that lower colt commander with ther dual back strip stippling gives me a bo@ner to no end. I take it,u did the work even, wow, no double wow that is awesome.

And you don't have to be a gentleman about it. LOL, I think most will tell u that is not ol jocko..

I wish I had the patience to do checkering like that. What that is, is a rubber coated aluminum mainspring housing that was sold by Pachmeyer many yrs. ago. Besides being light weight, the soft rubber won't wear through the lining of a outer garment like a checkered steel main spring housing will. Other things I did to keep the weight down as much as I could was to use a now discontinued Chip McCormick carbon fiber trigger, flattening and scalloping the top of the slide, and some other internals. It now weigh as much as an Officer's Model.

Yea! I did all the checkering, fitting, etc. All the stuff that didn't need machining like dove tail cuts, threading, hard chroming etc.

I don't know if you picked up on the joke. Some of the posts after the pictures, from bawanna, gb649, and I think some others preferred my wife's 1911 over the rest. I think they were being nice to her.

[xtriggerman]

Seems a couple of folks didnt read page 2 of this post! The gun did go back to CS and the new picture posted on the 1st page is a comparison of the new slide and barrel courtesy of Kahr as was explained here earlier. As far as why would I post the 2 pictures side by side? Iv been doing gunsmithing for over 30 years and have never seen a slide and barrel peaned away like the one I bought over the net. It was a surprise to me. This type of wear IS in fact possible with this design. As JG has said his "lighter" cast 9mm loads peaned up a couple of barrels that needed replaceing. New buyers should be aware of the possiblity of finding a used gun with a peaned barrel and slide. The good news is Kahr did good by me when I sent the gun back and replaced the worn parts free of charge. If kahr dumped that lifetime warrenty for a 5 year one, buying a used gun with this ware could be a $300 prospect of getting the gun to run safely. The P40 has alot going for it design wise but unfortunately the metalurgey is just not adaquit in the breech lock up. The 1911 has 3 lock up contact faces of a depth of .055" each. The kahr has one (rather small) lock up face of .040" on a cartridge that is nearly twice the working pressure of the 1911. That one design defficency will always be the achilies heal of this otherwise excellent firarm design. Everything else about the K is superb. Altho the canting angeled extractor could stress in time. My K40 will get a light diet of full house jacketed ammo simply because I want the gun to out last me, as is. I just shot a 8 round group with the front frame rested on a 4X4 off a table at 35'. The factory winchester 165gr fmj's printed a hair larger than 1". The used barrel Kahr gave me (for free) apparently shoots pretty good, just 1.5" low. Only a nut job would not be happy with that kind of factory performance. I hope this post puts the facts about these guns out there so "used" gun buyers will know what they need to look at. Most of these guns will probably never get shot enough to show a peaning but its still something that should be considered with the 5 year, your dime policy. Thanks to all who took the time to comment.

[jg rider]

Seems a couple of folks didnt read page 2 of this post! The gun did go back to CS and the new picture posted on the 1st page is a comparison of the new slide and barrel courtesy of Kahr as was explained here earlier. As far as why would I post the 2 pictures side by side? Iv been doing gunsmithing for over 30 years and have never seen a slide and barrel peaned away like the one I bought over the net. It was a surprise to me. This type of wear IS in fact possible with this design. As JG has said his "lighter" cast 9mm loads peaned up a couple of barrels that needed replaceing. New buyers should be aware of the possiblity of finding a used gun with a peaned barrel and slide. The good news is Kahr did good by me when I sent the gun back and replaced the worn parts free of charge. If kahr dumped that lifetime warrenty for a 5 year one, buying a used gun with this ware could be a $300 prospect of getting the gun to run safely. The P40 has alot going for it design wise but unfortunately the metalurgey is just not adaquit in the breech lock up. The 1911 has 3 lock up contact faces of a depth of .055" each. The kahr has one (rather small) lock up face of .040" on a cartridge that is nearly twice the working pressure of the 1911. That one design defficency will always be the achilies heal of this otherwise excellent firarm design. Everything else about the K is superb. Altho the canting angeled extractor could stress in time. My K40 will get a light diet of full house jacketed ammo simply because I want the gun to out last me, as is. I just shot a 8 round group with the front frame rested on a 4X4 off a table at 35'. The factory winchester 165gr fmj's printed a hair larger than 1". The used barrel Kahr gave me (for free) apparently shoots pretty good, just 1.5" low. Only a nut job would not be happy with that kind of factory performance. I hope this post puts the facts about these guns out there so "used" gun buyers will know what they need to look at. Most of these guns will probably never get shot enough to show a peaning but its still something that should be considered with the 5 year, your dime policy. Thanks to all who took the time to comment.

Hi xtriggerman
I was one that did read your page 2 post, but didn't go back to look at the new pictures. Having never handled a K40, now I'm curious about it's internal measurements, like the lug height of the barrel and the slide thickness from the top of the slide to the locking area, although I don't think that should matter, compared to my new K9 barrels and my older slide. Later after I have my first cup of coffee I'll take some measurements and post them. I'd appreciate if you would post your slide thickness since you say your barrel lug area is .040".

After looking at those before pictures again, it looks to me that the barrel was twisting. Because of the wear on one side of the bottom lug slot and the uneven wear on the barrel lug. Makes me think that the barrel was binding and not being able to drop down properly. What does the slide stop cross shaft look like? Is it gouged?

Back in my IPSC competition days, guys that were shooting comped .38 supers and such wanted to keep the barrel and slide locked up as long as possible. So when fitting a barrel they'd leave the bottom lug longer, so that the barrel and slide came back further before the link came around to pull the barrel down. It cause the upper barrel lugs to start to round off, never saw any wear on the slide lugs though. Different steel?
There was an article written in American Handgunner magazine about some barrel maker's bottom lugs actually shearing off. It was law suit time.

[jocko]

I had two barrel lugs on my Kel teck 32 auto break off. One in less than 50 rounds. never seen anything so pourous as those two barrels.

[jg rider]

Well I took some measurements on my K9. The barrel lug height from the top of the hood to the top of the barrel ring was .051" compared to xtriggerman's .040" on his K40 barrel. My slide wall thickness which the lower part is the lug area is .0995 from the top of the slide to the inside pad.

What was surprising is that using lay out blue shows that only about a little more then the top half of the .051" is contacting the slide lug area.
That's because the lower part of the slide lug is slightly beveled in, I think to help prevent peening.

IMHO, with the pressures generated, I don't want a .40 Kahr if that's all there is for a lock up. It may be O.K. if you don't shoot it much, but it won't work in our life style.

I realize that the bottom lug's horizontal portion of the slot holds the barrel and side together for the start of the travel slide, but?

[xtriggerman]

jg, this makes a great comparison between the 2 differing lock ups. The slide thickness on the new slide is exactly .150". I didnt measure the barrel lug its self but how much of it actualy rides up the .150 face. The barrel only uses bottom .040 of the .150 slide total thickness. The angular edges that move down away from the horizontal lock up area on the 40 do not actualy touch the slide at in battery position. They kant away as the barrel moves to top out in battery. The full lock up forces are only on the horizontal contact of .040" and .340" left to right. As the barrel begins to ware and pean in slightly, the .340 latteral contact will grow slightly. 1911 slides are hardened while the barrels are quite soft in comparison. You can take a good 1911 slide, put it in a bench vice and squeze the rails inward by .100 or more at mid slide and the rails will spring back to the original width when you open the vice back up. Thats why all the tightening is done primarily on the 1911 frame rails where the steel is not nearly as hard as the slide. I used to do all the customer returns at AO on the 1911A1s back in 1982 & 83. I dont remember what the Colt barrels rockwell'ed at but they were harder than the garbage castings that George Numrich made me put in the guns back then.
Billy Playford used to rifle all the numrich barrels on the original rifling machine that Springfield used to make Krag barrels on from 1896. One time he screwed up and a run of 200 1911 barrels had nothing but lines for rifling lands. Fred Nicholes, the shop office manager got the South African Gov. to take a 200 gun order on the cheap so they made me put those key hole specials in guns and ship em! about 5 months latter, we were shipping them 200 new Colt barrels for free.... Fred thought it was funny at first. ha ha......... bunch of nuckel heads. Kahr has got to be a BIG step up for the AO brand.